Laura Lambert wrote:

John Wong wrote: Laura Lambert wrote:  Tuesday, June 09, 2015, 9:16 Target container is coated with TaC. No Ta-heat shields are used. TGHT will be ramped up to 580A at 0.2A/min. TBHT will be ramped up to 230A at 01A/min. Chamber is currently being pumped down.  Tuesday, June 09, 2015, 15:37 HS water valves were opened. no leaks detected. Tapped up manually to 35A. Once vacuum stabilized after ~45min, initiated auto-ramp.  Wednesday, June 10, 2015, 08:02 IGP1 = 5.3e-7 Torr. TGHT = 250A and TBHT = 140A. Increasing auto ramp to 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.    Wednesday, June 10, 2015, 16:32 TGHT/TBHT are at 580A/230A for almost 6 hours, temp at 1728C. Vac at 8.5e-7 Torr.  Cooling down initiated at 1A/min. Target container should be inspected once the chamber is vented.    Thursday, June 11, 2015, 10:55 Vented in air and opened up this morning. Same as last container sintered in evap2 [IG-LIS for UCx#13] - ends not quite fully sintered and coating not very good. most likely due to old TaC spray. See link for photos. https://www.dropbox.com/sh/75o43x8y2z16e7j/AABc8Z1fTTaTRtJ5_Jr1eacWa?dl=0

 Monday, June 15, 2015, 15:24

Same problem also found for the LP-IG-LIS container, WO#40860-1, see elog id#215.  After re-coating and sintering, it seems better. 

For this container, it is re-coated and will undergo the sintering process one more time. 

Will try to go up to 1900C for the sintering process.

Target container is temporarily wrapped with 6.2cm of Ta foil as a layer for heat shield on each side of the tube, excluding the centre block.  The shield will be removed once the process is done.  

Target current will be controlled accordingly. 

Chamber is being pumped down. 

 Monday, June 15, 2015, 16:17

HS water valves open; no leaks detected. 

IGP1 at 6.8e-6 Torr and coming down.

 Monday, June 15, 2015, 17:21

Stepping up TGHT/TBHT to 60A, pressure seems pretty stable at 7.2e-6 Torr and coming down. 

Setting TGHT to 400A and TBHT to 230A, auto-ramping initiated.   Will setup up current to reach 1900C, if necessary. 

 Monday, June 15, 2015, 20:28

TGHT and TBHT reached 400A/230A, Temp at 1552C.  Vac at 2.7e-6 Torr.

Stepping TGHT

Monday, June 15, 2015, 21:16  

TGHT at 520A/9.06 V to achieve 1900C.  DV at 5.09V.  

Vac at 4.2e-6 Torr.  

Will continue the sintering process at this temperature for another 3-4 hours. 

 Tuesday, June 16, 2015, 00:15

Target container has been heated at 1900C for over 3 hours.  

Vacuum is coming down to 1.4e-6 Torr.  

Initiated cooling process at 2A/min

Chamber can be vented tomorrow and container should be inspected

 Friday, June 26, 2015, 16:04

Container looks good!